rebuild or replace, 711 with turbo

[mackmb212]

So I went to tarp my truck for the winter today, I checked the antifreez and it was about 2 gallons low so then I checked the oil and found it to be a greenish white color so I now know where the coolent went.I bought my truck back in the spring the first thing i did was change the oil and filter the old oil looked fine for how long i was told the truck was sitting, I only started it and moved it around at my garage a few times this summer and only let it run for about 15 min. My truck is no where near road worthy and will take a few years to restore. Would it be worth trying to rebuild the engine or find somthing newer to put in my truck I know 711 parts are hard to come by and they were not the gratest engines please tell me what you guys think or what you would do. my truck is a 63 b81 Thanks

Rudy

[BrianDzimitrowiczJr]

I think if that is the case i'd start looking for a 237. pretty straight forward swap. Maddog has more info

[mackmb212]

I think if that is the case i'd start looking for a 237. pretty straight forward swap. Maddog has more info

Thanks brian

[Maddog13407]

could be just as simple as a head gasket but if its leakin while sittin sounds like a liner. 711 parts are extinct. saw piston and sleeve sets sellin at the Sears oil action for $250 a hole and that was over my budget. id look for a 237 or 250 turbo and give me that old bullet haha

[Superdog]

might just be the oil cooler

[mackmb212]

could be just as simple as a head gasket but if its leakin while sittin sounds like a liner. 711 parts are extinct. saw piston and sleeve sets sellin at the Sears oil action for $250 a hole and that was over my budget. id look for a 237 or 250 turbo and give me that old bullet haha

when people say 237 or 250 what dose that mean. What is a 300 are these 70s or 80s engines

[39 Baby Mack]

I'd think along the lines of the oil cooler like Superdog said.

Can't be a liner leaking a 711 is a dry sleeve engine!

Ron

[mackmb212]

might just be the oil cooler

I dident think of that, is the oil cooler rebuildable.

[mackmb212]

I'd think along the lines of the oil cooler like Superdog said.

Can't be a liner leaking a 711 is a dry sleeve engine!

Ron

Thanks Ron

[staxx]

Yup check the oil cooler . But if you find anything major wrong or broke I would go with the 237.

[Maddog13407]

true, forgot about that myself! had 237 on the brain.

[Superdog]

when people say 237 or 250 what dose that mean. What is a 300 are these 70s or 80s engines

a 237 is the ENDT675 Maxidyne engine,and while they will work with a Duplex,Triplex,or Quad,they were designed to be used with the 5 and 6 speed Maxitorque transmissions.One of if not the best engine Mack ever designed.

A 250 is the ENDT673C Thermodyne engine,rated at 250 hp,with a operating range of 1500 to 2100 RPM,these were better suited to the B model transmissions.

Most of the time,what's referred to as a "300" is actually the ENDT676 Maxidyne rated at 283 hp.These had a tip turbine fan and intercooler set up,andlike the 237 were designed to be used with the 5 and 6 speed transmissions.These engines were available starting in 1973.

An actual 300 hp engine was introduced in 1980-81 as the E6-300,this was considered an Econodyne engine,with the front mounted air to air aftercooler.

[mackmb212]

a 237 is the ENDT675 Maxidyne engine,and while they will work with a Duplex,Triplex,or Quad,they were designed to be used with the 5 and 6 speed Maxitorque transmissions.One of if not the best engine Mack ever designed.

A 250 is the ENDT673C Thermodyne engine,rated at 250 hp,with a operating range of 1500 to 2100 RPM,these were better suited to the B model transmissions.

Most of the time,what's referred to as a "300" is actually the ENDT676 Maxidyne rated at 283 hp.These had a tip turbine fan and intercooler set up,andlike the 237 were designed to be used with the 5 and 6 speed transmissions.These engines were available starting in 1973.

An actual 300 hp engine was introduced in 1980-81 as the E6-300,this was considered an Econodyne engine,with the front mounted air to air aftercooler.

Thanks superdog for setting me straight on that, I guess if I go with a engine up grade I should look for a end673c those were turbo right ?

[jeffbyrne]

Thanks superdog for setting me straight on that, I guess if I go with a engine up grade I should look for a end673c those were turbo right ?

An END673C is a derivitive of the END673, both non Turbo.

The 250 is an ENDT673C, or it could be stamped T673C 'T' for turbo.

Do not be mistaken for an END673T which is a Turbocharged END673.

Are you confused yet?

Jeff.

[39 Baby Mack]

I'd remove the oil cooler and have it pressure tested, the earlier ones I believe were not rebuildable but the later ones had a removable tube bundle

inside that could be replaced.

All Mack six cylinder engines had dry sleeves in them until the E7 was made.

E7's have half wet and half dry cylinder liners in them (the top part on the liner is wet and the bottom part is dry).

Ron

[b61fred]

don't these engines have a head gasket problems anyway??? The oil cooler is the first logical choice most times there's oil in the coolant though. The orings on the ends of the cooler get hard and let the coolant slip by when cold. I suppose you could drop the pan and pressurize the cooling system, then see where the drip is coming from.

[fifth wheel]

Yes the 711's had head gasket issues.

FW

[oilburner]

a 237 is the ENDT675 Maxidyne engine,and while they will work with a Duplex,Triplex,or Quad,they were designed to be used with the 5 and 6 speed Maxitorque transmissions.One of if not the best engine Mack ever designed.

A 250 is the ENDT673C Thermodyne engine,rated at 250 hp,with a operating range of 1500 to 2100 RPM,these were better suited to the B model transmissions.

Most of the time,what's referred to as a "300" is actually the ENDT676 Maxidyne rated at 283 hp.These had a tip turbine fan and intercooler set up,andlike the 237 were designed to be used with the 5 and 6 speed transmissions.These engines were available starting in 1973.

An actual 300 hp engine was introduced in 1980-81 as the E6-300,this was considered an Econodyne engine,with the front mounted air to air aftercooler.

So there never was a tipturbine 300 built? And what was the deal with the tiptubine was it just a water to air cooler with a coolant fan in it or was there somthing eles to it. and i was thinking a e-6 was a 4 vavle engine.

[39 Baby Mack]

The first E-6's were 2 valve engines.

There were six cylinder's with series charge intercoolers on them (half water, half air) and tip turbines.

I don't remember what they were rated at but I believe they were over 300 H.P. and were designed to go with a multi-speed transmission.

Ron

[farmer52]

E6 4V came out in the mid-80s.

[terry]

The first E-6's were 2 valve engines.

There were six cylinder's with series charge intercoolers on them (half water, half air) and tip turbines.

I don't remember what they were rated at but I believe they were over 300 H.P. and were designed to go with a multi-speed transmission.

Ron

I do believe the tip turbine went to 315 horsepower. Terry

[b61mack]

I do believe the tip turbine went to 315 horsepower. Terry

The early 350s were series tip turbine intercooled, dont remember what year they came out.

[oilburner]

The early 350s were series tip turbine intercooled, dont remember what year they came out.

That is what i was thanking, but did not know they made a 350!

[Superdog]

That is what i was thanking, but did not know they made a 350!

Those first 350's were called a ENDT678 if I remember right,but shortly after renamed as a E6-350.First one I was around was in a '80 Cruiseliner demonstrator that our dealer was passing around to it's customers.

[oilburner]

That is why i love this page, it is full of mack pro's and people that have experience with the old macks, and every post i read i learn something! thanks guys i hope i can help out some of you guys sometimes.